Alarms and Staffing

NEWSLETTER ARTICLE

Premise: Staffing of the console position should be based upon steady state workload, with the operator-process system (alarms, displays, training, automation) designed to enable those individuals to be able to handle an upset when it occurs.

A recent Beville project involved a plant with plans to consolidate two board positions into one. An assessment of steady state workload showed that the consolidation was reasonable. An analysis of upset response was conducted, with a recent upset providing actual data on alarms and control moves. The assessment showed some problems, including the operators' ability to manage alarms, and so an alarm response analysis (rationalization) was undertaken. All alarms were reviewed with the operators and significant changes occurred in the total number of alarms and priority distribution. But how much would it help?

The upset event data used in the original analysis was re-examined in light of the new alarm system configuration. No attempt was made to assess the impact of alarm setpoint changes, just what was alarmed before and what would not be alarmed now. The results are shown in the table. Overall, a 40% decline would occur in the number of alarms actuating for that particular upset event, and the combined job would experience fewer alarms than Job B alone had during the initial upset. The total number of alarms is still high and further changes to reduce them are warranted, but this initial change from the upset that was experienced is significant.

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